Bar soaps are still widely used. With regard to cost and aesthetics, wear rate (also called use up rate) is an important property. Consumer perceived economy of bar soaps is determined by the amount of mush (also called slough) that occurs as the bar surface hydrates. The mush is considered undesirable by consumers since it is easily removed and washed off of the bar surface, leaving the user with less usable soap. Bar use up rate is another indication of the economy of the bar soap. Use up is determined by the physical abrasion (mechanical action) on the bar and is related to bar hardness and shape.
In addition to the economy of a bar, there is also a desire to maintain good foaming and cleaning abilities. The quality and quantity of lather produced by washing with a bar is associated with the cleansing ability of the bar. Other qualities desired are good rinsability, mildness to the skin, and delivery of fragrance to the user's skin. The combination of an efficient bar soap with effective cleansing and bar aesthetics has been often attempted.
U.S. Patent Application Publication Number 2003/0166480 describes certain ranges and combination of soap, synthetic surfactant, water, lower monohydric alcohol, humectant, structurant and gellant which can be used to bring about an excellent combination of desirable characteristics of a translucent or transparent bar composition.
U.S. Pat. No. 6,514,919 discloses a clear cleansing bar that does not form gel or mush, does not crack upon drying, and is non-irritating to the eyes. The clear bar composition in this reference contains dibenzylidene sorbitol (“DBS”) as the gelling agent. This reference does not, however, address non-clear cleansing bars composed of sodium soaps and is silent to the combination of glycerin and DBS.
U.S. Pat. No. 5,340,492, describes cleansing bars with a rigid interlocking mesh of neutralized carboxylic acids. The bars are cleansing bars with excellent smear properties.
U.S. Pat. No. 6,403,543, describes the suspension of particles in a bar soap. This suspension is achieved by using a gel matrix in which particles are suspended before addition to the soap mixture.
U.S. Pat. No. 6,310,015 describes a translucent/transparent/moisturizing cleansing bar.
It has now been found that a combination of DBS and glycerin gives an especially good product, especially as it relates to forming a soap bar which is not clear, and exhibits a longer life as compared to a DBS only bar. The richness of the aesthetics of the non-clear bar can also be enhanced by the inclusion of encapsulated fats/oils or emollient esters the form of beads.